Railway signaling system



Oct 6, 1953 J. E. WILLING ET AL RAILWAY SIGNALING SYSTEM Filed Nov. 9,1950 VII. i n z l: @v 0* m E .L #v nllv O\n U l u .3 u

M R. E F. am e D MM .w

m L v w. L J.. EL

THEIR Cttorneg Patented ct. 6, 1953 RAILWAY SIGNALING SYSTEM Joseph E.Willing,

Rochester, and Glenn 0. Ferm,

Gates, N. Y., assgnors to General Railway Signal Company, Rochester, N.Y.

Application November 9, 1950, Serial No. 194,842

2 Claims.

This invention relates to multiple block signalling systems, and moreparticularly pertains to a novel control of the wayside signals over aline circuit.

This invention is to be considered in the nature of an improvement inthe line circuit control shown and described in the prior application ofTizzard and Sebeczek, Ser. No. 193,338, led November l, 1950; and noclaim is intended to be made herein to any subject matter disclosed insuch prior application.

In prior conventional three indication block signalling systems, usuallya single pair of line Wires for each track section can be used tocontrol the signal governing that section by being deenergized whilesuch section is occupied and energized with one polarity when thesection in advance is occupied but energized with the opposite polaritywhen the second section in advance is occupied. These three conditionscan then be used to control the signal to give clear, caution or stopindications, depending upon the then existing trafc conditions. However,when the traic is relatively dense, three indication signalling mayrequire too great a spacing between the trains and it becomes desirableto employ four indication signalling.

In view of the above considerations, it is proposed in accordance withthe present invention to provide control for four indication signallingover a single pair of line wires by employing an added condition i. e.apply positive and negative energy alternately at recurring intervals.Such an organization then requires means which is not only distinctivelyresponsive to the different positive or negative line circuit conditionsbut which is also distinctively responsive to the intermittentenergization of the line circuit with opposite polarities alternately.

In accordance with the present invention, it is proposed to provide ateach signal two line relays in multiple in such a way that each receivescurrent only of the polarity to which it should respond, and each relayhaving such a structure as to respond only to its particular polarity.In addition, it is proposed that these relays be so constructed as tohave such slow releasing characteristics that both relays will remainpicked up when they are intermittently energized with their respectivepolarities of current.

One of the objects of the present invention might be said to provide anorganization as above generally outlined in such a way as to be reliableand protected against static discharges and the like. A further objectmight be said to be the provision of an improved line circuitelectro-responsive means to simplify the signal control under conditionsof impulsing.

Other objects, purposes and characteristic features of the presentinvention will be in part obvious from the accompanying drawing, and inpart pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to theFigs. 1 and 1A of the accompanying drawings which Show the circuitorganidation associated with a single track section of a multiple blocksignalling system. The reference characters used in these drawings havebeen selected to readily convey the relationships between the variousdevices and the respective signals. Fig. 1A is merely a diagrammaticshowing of a polarized relay used in the circuits of Fig. i.

For the purpose of simplifying the illustration and facilitating in itsexplanation, the various parts and circuits constituting the embodimentof the invention have been shown diagrammaticaliy and certainconventional illustrations have been employed, the drawing having beenmade more with the purpose of making it easy to understand theprinciples and mode of operation, than with the idea of illustrating thespecic construction and arrangement of parts that would be employed inpractice. The symbols (-1-) and are employed to indicate the positiveand negative terminals respectively of suitable batteries, or othersources of direct current; and the circuits with which these symbols areused always have current flowing in the same direction. If alternatingcurrents were employed, these symbols could be used to represent therelative instantaneous polarities of the alternating current.

Referring to the drawing, a stretch oi track has been shown as includingthe track sections 3T, 4T, and 5T. Each of these track sections, areassumed to have associated therewith the usual conventional trackcircuits employing a track relay at one end and suitable energy sourceat the other end. Since the particular characteristics of the trackcircuits are not involved in the present invention, only the track relay4TR has been illustrated for the track section 4T.

A signal is shown as located at the entrance to each track section, andthese signals may be of any suitable type. However, for convenience inthe illustration and description, it is assumed that these signals maybe of the searchlight type, such as shown, for example, in the priorpatent to O. S. Field, Patent No. 2,376,534, dated May 22, 1945. Thesignals indicated in the drawing along the aotaesi 3 trackway aredesignated i and 5; and these signals are represented by symbolsindicating that they are of the three position type. It is of coursewell understood that the conventional searchlight signal, such asdisclosed in the above patent, has a movable spectacle carrying threedifferently colored roundels which are moved to the proper positions togive the, desired signal indications. However, it is to be understoodthat a fourth indication is provided by these signals by causing theincandescent bulb associated with each signal to be intermittentlyenergized togive a flashing indication. Thus, a legend has been placedon the drawing to indicate thata fourthindication is provided by theflashing of the yellow aspect of the signal. In other words, a fourthindication rectifier units Ri and R2 which are respectively connectedbetween the windings of the two relays to allow the now cf current onlyin the direction to which the respective relays respond. The provisionof these rectiers thus reduces the normal current required on the linecircuits and also assists in rendering the relays slow acting. forreasons-presently to be explained.

Each of these relays is also constructed to have slow releasingcharacteristics by the provision of the usual copper slugs, or shortcircuited windings 43. Assuming the relay structure to be shown in theabove mentioned prior patent to Willingetal., the relay structurecomprises two is indicated by legend ratherthan by the form of Y thesymbols. Y

Two line wires are provided between'each pair of successive signals andthese line wires are provided with the diierent conditions ofenergi'zationin accordance with traffic conditions and have suitablerelay means associated therewith atrthe entrance end to each tracksectiorn For example, line wires I and Il extend between signals 4 and5; and line wires 31 and 38 extend between signals Brand i (signal 3 notshown). The line wires I and H have their energization controlled bycontacts. of relays SFY, EFL and SGYP at the. signal location inraddition to control by contacts of the track relay 4TH, whichenergization of the line wires i0 and Il selectively actuates the relaysGDR and lil-IR at the signal d. The line wires 3-1 and 38 haveftheirenergizaticn controlled by relays dFY, 4F11. and liGYP in a similarmanner. for governing the relays 3DR-.and 3HE at Signal 3 (relays andsignal 3 not shown). r

More speci-cally, thelinc4 wires Hi' and H' vassociated with tracksection 4T have energy supplied thereto in accordance with the conditionof relays SFY and GYP together with. theoperation of ya Hash-ingrelay-5Fl... These relays are of' the usual conventional type, while thenashing relay may be of any suitable type such as shown for exam-ple inthe. patent to. G.. Sr Field, Patent No. 1,969,665, dated August 7,19134. In this connection, it should be understood that such a flashingrelay may be replacedv any suitable coder or contactor operating: tointermittently open and'close circuits at a. suitable rate. Forthepurposes of the present embodiment-itis assumed that-the. flashingrelays operate` at a rateof 40 to 45 operations per.v minute.

At the entrance endof the track. sectiontwo relays 4BR and? lf-lillT-tlare connected. in multiple across the line w-ires- |'0 and lil subjecttocontroi by contacts; l2 and I3 oi the associated track relay NFR.These relays areV preferably of the type disclosed in the prior patenttoWilling. et all., Patent No.. 22,502,811, dated April 4,1950. rTheserelays respond to only one particular polar'- ity, and are soconstructed that the application of thev opposite polarity will. notoperate: such vrelays under even thel most extreme conditions.

Both relays are of course. alike, but they are connected to the line.circuit. so that. the relay lll-IR will respond to negativeenergy with`respect tothe line lwire mi, whereas'. the relay 4DR responds toposi-tive energyv with respect to the same line wire l0.. y

These relays IDR- and lll-IR (one of which. is typicall-yA shown inFig.. 1A). are both. provided with two aiding windings lillandr 41|...end two core membersl interconnected at one end by a back yoke E5 Aandhaving a cooperating armature 46 adjacent their other ends. Suitablepermanent magnets 41 are connected across the core members at their endsadjacent the armature, and a slotted magnetic leakage strip 48 isincluded iny multiple with the permanent inagnets to render ther relayhighly imm-une to energyof the lopposite polarity; The windings of therelay are located on the two core members between the permanent magnetsand the, .back yoke connecting the core members. It is of course ,tobeunderstood in this connection that the permanent magnet is of such astrength andthe back yoke is of suchV a cross section that'itf issaturated by fluxirom the permanent magnet alone all as disclosed anddescribed in detail in the above mentioned patent. Also, the armatureisbiased away from the core members to a suincient degree that itwill notbe actuated by the magnetic flux of the permanent magnets nor will itremain an actuated position. due to such nur from the permanent magnets.In using such av relay in the embodiment of the present invention,copper slugs i. e.- shortvcircuited windings 43, are insertedbetween thepermanent magnet and the windings. rlhese copper slugsy serve to delaythe decay of magnetic flux produced by the windings which. Vpassesthrough the armature toy actuate it, all for reasons well understood tothose skilled in the art.

Associatedwith the relays LHR and 4DR,- is a conventional neutral relaylil-ID controlled by the contacts i4 and. i5 of these relaysrespectively. Thus the. relay li-HD- is picked upwh-en either or both ofthe relays @HR and 3DR are picked up.

A.. slow pick uprelay 4D is controlledv bythe relays 4i-IR and 4DRthrough contacts i6 and 1:1 inseries. This relay 4D may be mad-e slowtopickup by any ofrt'he usual means- The signal Il'hasbeen.diagrammatically illustrated vashaving an. operating mechanism VM,contacts i9; vand. 26,. and an incandescent larp-p L. The contacts i9and Zilare showninrtheir positions. when. the mechanism M is energizedto a green. indicating positionj and the contact i9 assumes a righthandposition when thetsi'gnal iscauSed to indicate-yellow, whereas, thecon.- tact Zdis causedtoassurne a right handpositionxwhen the signalisoperated to indicate yellow ori is at stop. These contacts |91 and-20are connected in the usual way to control-.socalled .green-yellowrepeater relay This relay IGYPhasa Contact 22 which. in series', withthe contact 23 of relay 4DR contro-ls the relay QFY. This relay @FY inturn supplies energy through trent. contact M to the flashing relayAFL.v 'Ehe'.flashing. rel-ay 4FT.. has been Vccnverr tionallyillustrated as having. a self-interrupting contact. 25.. These;- relays4FY and AFL together "with the slow pick up relay 4D are eective togovern the energization of signal lamp L.

It is to be understood that the relays 5FY, SGYP, and EFL associatedwith the signal 5 are controlled in exactly the same way as thecorresponding relays at the signal 4. Thus, it can be understood thateach section of the stretch of track has apparatus associated with itsimilar to that shown for the track section 4T.

It is to be understood that the present invention may be applied to astretch of track associated with a stretch of automatic signalterritory, with a centralized trailc controlling system, or with astretch of track between interlocking plants Where the operators may attheir discretion determine when the signals for the stretch of track areto be cleared. For the purpose of the present disclosure it is assumedthat the track section shown is in automatic territory, and energy isapplied to the line wires extending from the exit end of the stretch, soas to cause the rst signal of such strength to give the properindication, and then each succeeding signal to the rear area is properlycontrolled in accordance with the traiic conditions. Thus, all of thesignals are normally cleared. In any case, the operation of the systemis exactly the same upon the passage of a train.

Operation Let us assume that energy is supplied to the line wires of thelast section of the stretch so that all the signals of the stretch arecleared. Under these conditions, the relay 5FY is energized closing itsfront contacts 26 and 2l. This relay SFY, when energized, causes thehashing relay EFL to operate, the same as shown for relay 4FL associatedwith signal 4. Thus, the contacts 28 and 29 of the relay 5FL arealternately picked up and dropped away at some suitable rate, such as 45times a minute. This causes opposite polarities of energy to be appliedalternately through front and back contacts 28 and 29 of relay BFL andthrough front contacts 26 and 2'I of relay EFY to the line wires IIJ andII.

It is of course assumed that the track section 4T is unoccupied, so thatfront contacts I2 and I3 of track relay 4TR are closed. Thus, the pulsesof opposite polarity are applied to relays 4HR and 4DR in multiple, butwhen the upper wire IB is positive, energy ows only through the relay4DR by reason of the rectifier RI. Likewise, when the upper wire I0 isnegative, energy ows only through the relay 4HR by reason of rectifierR2. Thus, each relay intermittently receives energy of the particularpolarity to which it is capable of responding, so that its contacts `arepicked up and maintained in a picked up position by reason of the slowacting characteristics of that relay.

Since each relay 4HR and 4DR includes a rectier unit of any suitabletype, such :as a dry plate cop-per oxide, or selenium cell type, currenthows through the relay only in a direction to pick it up. When thecurrent ceases, the flux can be maintained by the copper slugs to givethe desired time delay. Also, the short circuit through the two relaysin multiple tends to increase the delay time. This delay or release timeis of course long enough to bridge the time between successiveenergizations of like polarity, so that the relay remains steadilypicked up. This not only avoids Wear on the relay itself but alsoobviates the necessity of additional de- 6 coding means as required inprior systems of this kind.

With both the relays 4HR. and 4DR, picked up. contacts I4 and I5 bothsupply energy from to the relay 4HD. Also, the contacts I6 and I1 areboth closed so that the circuit to relay 4D is completed. These relays4HD and 4DP then control the signal 4 to cause it to indicate a green orhigh speed proceed aspect. More specically, a circuit is closed for themechanism M of signal 4 from (-1-), through a circuit including front-contact 30 of relay 4HD, front contact 3| of relay 4D, winding of themechanism M, and front contact 32 of relay 4D, to With the signalmechanism thus energized, it is operated to a position to give a greenindication and the lamp L is energized by reason of the closure of frontcontact 33 of relay 4DP. In this manner, the signal 4 is caused to giveits most favorable proceed indication, which is a green signal lightbeam.

It should be noted that when the signal 4 indicates green, the relay4GYP is energized from (-1-), through a circuit including contact I9 ina left hand position, contact 20 in a left hand position, and windingsof relay 4GYP, to This energization o1 relay 4GYP closes its frontcontact 22 which completes the circuit for the relay 4FY since under theconditions assumed both relays 4DR and 4HR are steadily picked up. Therelay 4FY in turn closes its front contact 24 to supply energy to theiiashing relay 4FL which by reason of its self-interrupting contact 25operates intermittently to open and close its back Contact 34. However,at this time the contact 34 is ineiective because the relay 4D isenergized.

It is obvious that if a train traveling on the track section 3T shouldaccept the green indication displayed by signal 4 and enter the tracksection 4T, the track relay 4TH would drop away opening -contacts I2 andI3 thus deenergizing the relays 4HR and 4DR. This would result in thedeenergization of the mechanism of signal 4, and its operation to itsstop position would deenergize the relays 4GYP and 4FY. Thus, the lamp Lwould be steadily energized by reason of back contact 24 of relay 4FY,regardless of the particular position which the flashing relay 4FL (orother coding mechanism) might assume.

While a train is in a track section in advance of a signal, theapparatus at that signal location causes negative energy to be suppliedto the line wires to the next section in the rear. For example, assumingthat a train is on the track section 5T, the relays 5FY and EGYP areboth deenergized so that is connected through back contact 35 of relaySGYP and back contact 26 of relay 5FY to the line wire Il. The returncircuit from the line wire II is completed through back contact 21 ofrelay SFY and back contact 35 of relay EGYP, to This steady negativeenergy causes the relay 4HR to be picked up in turn energizing the relay4HD. But since the relay 4D is deenergized, the energy supplied throughthe front contact 30 causes the signal mechanism M of signal 4 to beoperated to its yellow indicating position. This closes contact I9 in aright hand position and energizes the relay 4GYP. The relay 4FY is notenergized since the relay 4DR is deenergized. Thus, back contact 24supplies steady energy to the lamp L so that the signal 4 can display ayellow indication.

Then the train Vmoves from the track section T into the track section 6Tbeyond signal (not shown) ,the relay 5GYP is picked up which causes VMof signal 4 is maintained in its yellow indicating position energizingthe relay AGYP. However, under this situation,the relay IDR is picked upso that the circuit 'for relaydFY is completed through front contacts 22'and123. This sets the hashing' relay 1FL into operation, and with theback contact .id/openv energy for lamp L is intermittently suppliedthrough back contact 33 of relay "4D and back contact 3d of the dashingrelay 4F11. Contact M of the flashing relay is intermittently opened andclosed so as to cause `the lamp 'L to flash vand thus cause the signalrestrictive, fsl-loh a failure Wou-ld be entirely Ssafe.

When the tra-in moves out of the track section V5T into 'the tracksection' 1T beyond signal 1 (not .shown-i, the conditions are 'repeatedso that at signal 5 the relay `5FY is `p'ick'edup which causesrv'oper-ation of the .flashing relay 5Fl :and thus 'causes thelinefwiresl' and H 'ito'be' alternately 'energized with opposite polarit'es at theselected rate. This causes 'the `signal f4 to :be :controlled 'to giveits green Yproceed indication, as previouslydescri'b'ed.

'Having thus described the control of the block signalling :system asone specific embodiment fof the present invention, it is desired'to heunderstood that ytl'iis particular form iis sel'e'ctedto facilitate inthedi'sclosure'of 'the -nventionrath'er than to limit ythe number ofJforirifs which it may assume; and, vit is to be Afurther understoodthat various modi'cations, adaptions and alterations the requirement ofpractice, without i-n any manner departing fr'omfthe spirit or scope 'of4the present invention.

11. In combination, va ysection 'of railwayftracn a signal `forgoverning 4traiic 'over said section,

"8 two conductors extending from-said signal ,locad tion to the otherend of said sectionat which energy is applied to said conductors inaccordance with traffic conditions, one polarity being applied when thenext section in advance is occupied, the opposite polarity being appliedwhen the second section in advance is occupied and both polarities beingalternately applied at intervals when the third section in advance isoccupied, two signal control relays at saidV signal location 4connectedin multiple across said conductors each havinga rectier included Vinseries with its windings, said rc'terswbeing oppsitel'y connected topermit theenergization of only one relay in response toV either polarityof energi'zationl of said conductors, and veach 'of said relays having'slow actingstructural characteristics, one of `said relays having apermanent magnet associated therewith to render it responsive to only aparticular polarity and the other' having a permanent magnet associatedtherewith for rendering it responsive to only the opposite polarity,said relays both being steadily actuated in response to the intermittentalternate application of both polarities, and signal control circuitsgoverned by said relays for causing said signal to give differentproceed indications dependent upon whether one 'or the other or both ofsaid signal control relays are actuated.

2. In combination with a circuit having current of either polarityapplied thereto and at times pulses of opposite `polarities alternately,two polarized .relays connected in multiple Vto .said circuit so as torespectively respond to opposite polarities, each of said polarizedrelays 'having a permanent `magnet connected across its core .membersadjacent its arma-ture to render A:that relay responsive to energizationof only one partcular polarity, short circuited windings snr- .roundingits core members. adjacentlsaid permanent magnet to render the armatureAof that relay slow in releasing, a rectier unit .connected in serieswith each vof said :relays to allow .current now in :a fdirection`through its respective relay corresponding 'to ithe direction ofcurrent low :to which that relay will respond, whereby said relaysselectively respond to the polarity of energy .on .said `circuit and'both sof said relays lremain steadily operated when' 'said circuit is.energized "with pulses of :opposite polarityalternately.

References 'Gited in the ,iile of this patent 'UNIT-ED' STAIES PATENTSNumber ame Date V,2,107,162 Preston Feb. l, V19.3.8 v2,126,658 PastererAug. .9, 193.8 2,177.6,51-1 Pelikan. oet. 1.7., 1939 12,361,516 WellsOct. 3-1, .1944 2,486,086 Willi-rig -et al. 00h25, .1949 2,502,811Wi'llngzetfal.; ADRA, 1-950

